Cutting torch



- March 0, 1945. D. A; MARRA" 231L910 CUTTING TORCH Filed Dc'. 5, 1941 INV ENTOR 09M Z- m 6 BY MW/J Z'MMz ATTORNEYS Patented Mar. 20, 1945 UNITED STATES iDTENT OFFICE CUTTING TORCH Daniel A. Marra, Cheswick, Pa. Application December 5, 1941, Serial No. 421,752 4-Glaims. (Cl. 158-274) This invention relates to cutting torches: instruments that are used for burning kerfs through metal articles, such as steel beams, for the purpose of severing them. The objects in view are simplicity of structure and efficiency in service. I r

In the accompanying drawing Fig. I is a view in side elevation of a cutting torch in whose structure the invention is embodied; Fig. 11' is a view to larger scale showing a portion'of the torch in longitudinal and horizontal section, on the plane indicated at II-II, Fig. I; Fig. III is a View in transverse section, on the plane indicated at III-III, Fig. II; Fig. IV is a view to equal scale with Figs. II and III, showing in longitudinal and vertical section the tip-carrying delivery end of the torch of Fig. I;' Fig. V is an endview of the tip in elevation; and Figs. VI

, tion may be established with sources of oxygen and VII are views to yet larger scale, showing in fuller detail portions of the structure shown in Fig. II, and in Fig. VI certain movable parts are shown in positions that are alternate to those shown in Fig. II.

A cutting torch is an instrument that a workman carries in his hand and applies to the work.

It is connectedto supplies of gas and of oxygen under pressure, and the connections are flexible, that the instrument may be freely manipulated.

The requisites of a cutting torch are that it shall deliver throughitstip, and successively as operation progresses, first a heating flamethat, brought to play upon a steel beam, for instance, shall bring the metal in the region of immediate attack to the temperature of combustion. When such temperature has been attained, it is requisite, second, that the torch shall deliver to the so heated region a stream of oxygen. The oxygen so delivered burnsthe heated metal, and the burning of the iron releases heat, so that, without further supply of fuel through the torch, the work is progressively, beginning with the region of initial heating and continuing therefrom, brought to the temperature of combustion, and progressively burned away in a kerf that, with proper manipulation, extends in the plane in which the jet of oxygen is delivered. Additionally, it is a matter of convenience, and a practical requisite, that at all times when the torch, though not in use, lies ready for use, a, pilot flame shall be burning from its tip, to aiiord ignition when the torch is taken up and put to use.

Referring to Fig. I of the drawing, a torch is shown that, in general features, is of familiar form. It consists essentially of a body I, a head 2,

and interconnecting pipes 3, 4, and 5. The body under pressurev and of fuel gas under pressure.

Within the body I passageways are formed,

through which oxygen may flow to pipes 3 and d and as to pipe 5. Those, passageways are sub ject to control byvalves, as presently will be explained. -The head 2 of the torch-carries the removable and replaceable tip 8, The tip is cylindrical, and is formed with an axial bore that emerges through a central orifice 9, and with passageways and a mixing chamber that opens through a plurality of circumferentially arranged orifices I ll. Within the head 2 are passageways through which the oxygen pipe 3 communicates with the axial bore of the seated tip, and the oxygen pipe 4 and the gas pipe 5 communicate withpassageways in the seated tip that lead to the mixing chamber. These features are known to the industry, andrequire no fuller statement It is already known that valve control may be provided, to establishthe three conditions named below: .(1) flow at low rate of oxygen and of gas through pipes 4 and,5, while fiow through pipe 3 is cut off, so that no more than a pilot flame burns from orifices l0; (2) flow at high rate of oxygen and of gas through pipes 4 and 5, while flow through pipe 3 is out 01f, so that a heatingflame burns from orifices Ill; and (3) flow of oxygen through pipe 3, while flow of oxygen and of gas through pipes 4 and 5 isreduced to the low rate first named, so that cutting oxygen is supplied through orifice 9 to the heated work, while only a minimum flame burns from the orifices Hi. In cutting torches that heretofore have beendevised, the several valves by which these several lines of fiowthrough the torch have been established have been provided with independent meansof adjustment and control, and in consequence the workman in the pro-gressof operation has had to pause, remove the torch from application to the work, and, while holding the torch in one hand, to make valve adjustment with the other.

In the torch of my invention three valve chests H, 12, and I3 are formed in the body I of the torch. 'They are essentiallycylindrical, and the The valves within the chests are made subject to shifting means under the control of the workman in the grasp of the hand that holds the torch. From the forward end of the body I of the torch extends a stock, conveniently in the form of a cylinder 14 surrounding the pipes 3, 3, and 5. This cylindrical extension constitutes the handle by which the workman takes the torch in his grasp and moves it as he will. A lever I5 is pivoted to the body 1 of the torch at [6, and the power arm of the lever (it is in this instance a lever of the second kind) extends longitudinally of and adjacent to the handle It, so thati om with the handle within the grasp of the workman in his use of the torch. The range of swing of the lever may be adjusted by means of a screw l1 upon which the heel I8 of the lever when swinging clockwise (Fig. II) makes abutment. My invention consists in bringing the three valves within the three valve chests under thefcontrol of this single lever, and in so designing and proportioning the valves that, pilot-light flow alone being normal, proper swinging of the lever will establish in succession or in alternation either of the other two of the three conditions of operation defined above.

In Figs. .II and VI I have shown in detail the valve chest 12 and the valve Wit n it, Through this valve chest air flows to pipe 4 and, as will be understood from what has gone before, air flow through this valve chest is always maintained, either at the low rate requisite to th maintenance of a pilot flame through the orifices floor at the high rate requisite to the maintenance of a heatin flame.

Within the valvechest is arranged a valve block is, adjustable in its position, by virtue of its screw -thread mounting in the essentially cylindrical chest, as best shown in. Big. .VI. The valve block is axially perforate, andthrough the perforation extends the stem? .of a valve 2| that seats from above downwardly upon the valve block 19. The valve .2! is provided with .a by-pass of limited and predetermined size, convenientl-y in the form of a perforation 2.2 hat penetrates the valve body. Extending through the axial perforation in the valve block (the perforation is of a size to .allowflow at maximum rate through it and around the valve stem) the .stem .25) abuts upon a ball valve 23 backed .by a spring .24. The ball valve seat upwardly (as seenin Fig. II) upon the lower end of the per..- foration through the .valve .block. The drawing shows that the valve block l9 and the valve 2| are provided with facings 25 and 2,1 of suit.- able material, to attend tight closure of valve 23 upwardly and valve .2] downwardly. A passageway 28 leads from the source of oxygen supply to the valve chest beneath valve .block J9, and .a passageway 29 leads from the valve chest above the valve block to the oxygen pipe 4. In the passag-sway 2,8, as shown in Figs. II and VII, a valve 3,!) is set, to flX at proper value the efiective size .of the passageway. The valve stem 29 protruding through the head of the cyl ndrical valve shes-t is arranged to :be engaged by the lever 1.5 and to beshif-ted when the lever isswung counter clockwise, Fig. II.

It will be seen that the tension of spring 24 is exerted to (carry valve .23 toward its seat and to shift the stemlil upward. In the assembly the lever is by the adjustment of screw I! so set that the abutment of the valve stem 2.9 upon it is effective to limit the range of spring impelled advance of valve 23 and to hold valve 23spaced from its seat .at such slight interval as allows passage of an oxy en flow sufficient to maintain a pilot flame at the burner orifices it, but not more. As the lever is swung (counter-clockwise, Fig. II) the interval at which valve 23 is held remote from its seat is widened; and while 5 by the same swing of lever 15 the valve 2| is caused to advance toward its seat, the effective opening of this valve 2| is not during this earlier portion of the range of swing of lever i5 diminished. The consequence then of the swing of lever l5 through this earlier portion of its range is that the rate of flow of oxygen is increased and (the parts being properly proportioned) is brought to a value adequate to sustain a heating flame at the burner. Further swinging of the lever I5 is efiective to seat valve 2i and then, although valve 23 is opened wide, flow of oxygen is through by-pass 22 only, and this by-pass is such size as to permit flow at a rate sufiicient only to sustain a pilot flame. Thus the three conditions of oxygen flow through pipe 4 are established; (,1) norm l fl w t l w r t d quate for the pilot flame only; (2) flow at aocelerated rate, adequate for the heating flame; and L3) flow at a rate reduced again to that adequate for the pilot n me only' When pre sure upon lever I5 is relieved, the tension in spring 424ris exerted through stem upon .the lever, tending to swing it clockwise, Fi If, As thelever-swings clockwise from po ition of cutting (at the extremity of its range.) back o inactive positio the flow of oxygen, .mome t v augm nt 'd is immediately r du ed a a and the pilot flame is maintained, burning from the t p A body of pa king 34 isprovided tor the: stem ,20 mite passage through thahead .35 of the valve chest, and a springzi cts upon the pack ng-to make it effective. This spring may find backing, as shown, in thebody f valve and in h case th stren th of the spring will not l os 40 great as to interfere w th the operation of sprin backed valve 2.3 in the manner described.

Comparison of Figs. 11 and 11 will show th three valve chests H, 12, and 13, to .be grouped, with h st 4 somewhat in dvance (to the left) and chests and 43 in side-by-s'ide positions. This is a convenient, though not an essential g oupin The figures also show the lever 15 to .be widened laterally into a plate 3| that overlies the entire group ng.

The valve chest I3, th ou h which f l ga flows, and the valve structure within it may b understood to be in all respects substantially identical with chest l2 and its valve structure. already described, with this single qualification: that the stem ,32 of its valve protrudes upwardly to such .slighter degree as to be borne upon .by the plate 31 of lever 15 simultaneously with the valve stem .29 (the difierence in the distances of the two stems from the fulcrum point of the lever necessitates this-falthough,alternately. the

plate 31 mightmanifestly be shaped to afford th same compensation). Without further explanation' it will he understood that the flow of ga through :pipe 5 is thus .co-ordinated with the flow of o ygen hr u h pipe 4, to the end already described, that norm l y a pilot flame emerges from the tip 8 and that in the range of the swing ,oflever 15 two succeeding conditions-are estabished: first, of how adequate to produce ..and sustain a heating flame, and, econd, flow that is diminished again to that which suffices for a .p lotflame and no mor As already noted, the valve 3B maybe adjusted tofix at proper value the :size of the passage 28. Anidentical valve is set in the .passageway lead- 1 2,871,970 'ing from the gas inlet 1 to the valve chamber l3,

and thus it is that theefi'ective size of the oxygen and gas passages leading to the'pipes 4 and 5 may be fixed, and the torch (ina manner familiar to the art) adapted to the use of tips of various sorts and sizes. v I

Facility in the adjustment of the valves 30 is gained through a refinement in the structure of the lever-adjusting stem ll. Specifically, the upper end of the stem (Fig. II) is provided with a' tip Ila of polygonal cross section, and inthe outer end of each valve 30 (Fig. VII) a comple mentary socket 30a is formed. Manifestly, the stem 17, upon removal from normal position of service in body I, may be used as a socket-wrench in adjusting thelvalves 30. Thus, the stem ll becomes an efl'ective instrumentality for adjusting the positions of the several valves described, and, since it is itself an essential element of the structure, no other tool is required, and the torch is complete and completely serviceable in and of itself. There is no ancillary tool to be lost or forgotten.

The third valve chest ll contains a valve that normally is held closed. The valve is unseated by the abutment of the advancing plate 3| of the lever l5 upon the stem 33; and, as illustrated in Fig. II, the stem 33 of this valve extends up ward for such limited distance that it is only after the heating-flame controlling valves have been shifted and a heating flame has been caused to spring from tip 8 that further swing of the lever I 5 in counter-clockwise turning (Fig. II)

. will unseat the valve in valve chest H. The unseating of this valve opens the line of flow from the source of oxygen under pressure through pipe 3 to the axial bore in tip 8 (at the same time, as has been explained, the flame from the tip is diminished to pilot-flame magnitude). The oxygen that then flows through pipe 3 and has exit through orifice 9 0f the ti is of a magnitude adequate for cutting purposes. The swing of the lever is, it will be seen, unidirectional in efiecting the successive valve shifts.

The valve structure within the valve chest H may be understood to be a counterpart of that Within valve chest 12, shown in Fig. II, with this qualification, that, while the stem 20 (33) is retained, the valve 2| is omitted, and the spring 25 also is omitted. The valve 23 then, under the tension of spring 24, is effective to cut ofi flow until, on the swing of IE to the limit in counter-clockwise direction, Fig. II, the thrust of the stem 33 unseats the valve. Only then is cutting-oxygen flow established.

In operation, beginning with the parts in the positions indicated in Fig. II, it may be understood that gas and air connections have been made, the proper cocks turned, and that a pilot flame is burning from the tip. The workman takes the torch in hand, grasping it by the stock M. The normal position is that shown in Fig. I, with the tip 8 directed downwardly. Naturally then the palm of the workmans hand engages the handle on the farther side, the thiunb lies along the upper surface of the stock, and the finger tips come naturally to rest upon the lever I5. The workman presses upon the lever and swings it until he produces a heating flame, springing from the tip. This he may easily do, and may easily maintain such position of the lever indefinitely. When he has applied thev heating flame to the work and has continued the play of flame upon the work until proper temperature burning from the tip.

has been gained, he increases pressure, swings lever 15 all the way, and in so doing causes cutting oxygen to spring'ina-jet from the tip. Under itsinfluence the metal burns away and the kerf is cut. Should the heat fail, relaxation of pressure will re-establish the heating flame in place of the oxygen jet,'and; then, when temperaturehas been regained, oxygen maybe applied again; When the jobisflnishedlever I5 is released, and again a pilot flame isv reestablished,

When the torch goes out of service, as at night, for instance, the adjusting screw ll maybe retracted, and the valves 23 allowedto close.

I claim as my invention: I

1. In a cutting torch having a torch tip carried by a body including ,a passage for gas, a passage for heating oxygen, and'a passage for cutting oxygen, said bodyincluding valve chests arranged severally in the lines of flow through said passages, valves equipped with'valve stems organized with said valve chests severally, the valve of said cutting oxygen passage being movable between passage-closing and passage-opening positions, the valves of said gas and heating-oxygen passages including means operative in the unidirectional shift of the valves first to increase and then to diminish the effective size of the two passages, and a movable member adapted in the course of unidirectional movement flrst to shift the stems of the gas and heating-oxygen valves through the flow-increasing .portion 'of their range of valve-shifting movement, and then, in its further progress, stem of the cutting-oxygen valve from closed to open position while continuing the movement of the gas and heating-oxygen valve stems through the flow-diminishing portion of their range of valve-shifting movement.

2. In a cutting torch, a body in which are included three passageways, one passageway for gas, onefor heating oxygen, and one for cutting oxygen, a valve chest arranged in each of said passageways, three valve structures arranged in said valve chests severally with valve stemsextending all from a single face of the'torch body, a lever pivoted to the torch body and adapted in its range of swingto bear upon such projecting ends of the valve stems and shift them, the bearing of the lever upon the valve stems of the gas and heating-oxygen valves being effected in an initial swing, and the bearing upon the stem of the cutting-oxygen valve being eiTected by a further swing ofthe lever in the same direction,

the valve structures whose stems are so first engaged being adapted to afiord first an enlargement and then a diminution of the eiiective size of the gas and heating-oxygen passageways in which they are included, and the valve structure whose stem is last engaged being adapted to open the otherwise closed cutting-oxygen passageway in which it is included.

3. In a blowpipe including a body having two passageways, one passageway for gas and one for oxygen, a valve chest in each passageway, a valve structure in each chest, and a valve-operating device for each valve structure; the invention herein described comprising in each valve chest a passage arranged in the line of flow through the chest, the valve structure in the chest including two valve elements arranged for cooperation, one with each end of said passage, the valve-operating device comprising a stem extending through said member and serving to hold said valve elements spaced apart a greater additionally to shift the distance than the ieasth 9 ssid'ssssegera sprin ncrm-allv ur in cne or the va ve-elemen s t9:- wards flow i ibitine, position over ens-e d .oz said passa e, with" the sec nd a ve elemen spac d from the other end oi-the passage. and means *for sh fti the valve'stcms .Qf b th va ve structures 0 s ift th fi t valve el men pf .bcth out of flow-inhibitin p sition and the second valve element of both towards flow-inhibiting posit-ion relatively to the ends -.0f,the p ssages through which the valve Stems xel tendem e. Icy-pass arranged with each valve structure to afford .a restrictedsflow-onfwgas and oxygen when the second valve elements enter fl w-inhibiting position.

4. In a blowpipe includin a body havin two passageways, one passagewaytiorgas and une for oxygen, a valve chestin each assageway, a valve structure in .each chest, and a valvesoperating device for each valve structure; the invention herein described comprising in each valve chest remember ha n as passa e arranged in the line ef flow throu h the ehestthe va ve streetse the che t incl din t o valv elements arranged fer ccvperaticn, one w th e ch end of said passa e, s id va v e e nts be n spac d a eater distance than the distance between the ends of s id pass ge and mea s no a gi g the first of the valve elements towards flow-inhibiting-po- .sition relatively to said passage, with the second 

